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1.
J Anim Sci ; 1022024 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-38502533

RESUMO

Consumption of ergot alkaloids from endophyte-infected tall fescue results in losses to the livestock industry in many countries and a means to mitigate these losses is needed. The objective of this study was to evaluate intra-abomasal infusion of the dopamine precursor, levodopa (L-DOPA), on dopamine metabolism, feed intake, and serum metabolites of steers exposed to ergot alkaloids. Twelve Holstein steers (344.9 ±â€…9.48 kg) fitted with ruminal cannula were housed with a cycle of heat challenge during the daytime (32 °C) and thermoneutral at night (25 °C). The steers received a basal diet of alfalfa cubes containing equal amounts of tall fescue seed composed of a mixture of endophyte-free (E-) or endophyte-infected tall fescue seeds (E+) equivalent to 15 µg ergovaline/kg body weight (BW) for 9 d followed by intra-abomasal infusion of water (L-DOPA-) or levodopa (L-DOPA+; 2 mg/kg BW) for an additional 9 d. Afterward, the steers were pair-fed for 5 d to conduct a glucose tolerance test. The E+ treatment decreased (P = 0.005) prolactin by approximately 50%. However, prolactin increased (P = 0.050) with L-DOPA+. Steers receiving E+ decreased (P < 0.001) dry matter intake (DMI); however, when supplemented with L-DOPA+ the decrease in DMI was less severe (L-DOPA × E, P = 0.003). Also, L-DOPA+ infusion increased eating duration (L-DOPA × E, P = 0.012) when steers were receiving E+. The number of meals, meal duration, and intake rate were not affected (P > 0.05) by E+ or L-DOPA+. The L-DOPA+ infusion increased (P < 0.05) free L-DOPA, free dopamine, total L-DOPA, and total dopamine. Conversely, free epinephrine and free norepinephrine decreased (P < 0.05) with L-DOPA+. Total epinephrine and total norepinephrine were not affected (P > 0.05) by L-DOPA+. Ergot alkaloids did not affect (P > 0.05) circulating free or total L-DOPA, dopamine, or epinephrine. However, free and total norepinephrine decreased (P = 0.046) with E+. Glucose clearance rates at 15 to 30 min after glucose infusion increased with L-DOPA+ (P < 0.001), but not with E+ (P = 0.280). Administration of L-DOPA as an agonist therapy to treat fescue toxicosis provided a moderate increase in DMI and eating time and increased plasma glucose clearance for cattle dosed with E+ seed.


Fescue has become the dominant cool-season perennial grass in the southeastern region of the United States and is also found in other countries. Endophytes from a plant­fungus symbiotic relationship produce toxic alkaloids that have caused significant annual economic losses to the livestock industry. Treatments to alleviate this toxicosis are still demanded. This study evaluates the infusion of the dopamine precursor, levodopa (L-DOPA), to mitigate the toxicosis caused by ergot alkaloids. When L-DOPA was infused, eating duration increased and the decrease in feed intake caused by ergot alkaloids was less severe. Additionally, circulating dopamine and glucose clearance increased with L-DOPA. These results suggest that L-DOPA has the potential to aid in the mitigation of the toxicosis caused by ergot alkaloids.


Assuntos
Alcaloides de Claviceps , Festuca , Lolium , Bovinos , Animais , Alcaloides de Claviceps/toxicidade , Levodopa , Dopamina , Prolactina , Ingestão de Alimentos , Endófitos , Norepinefrina , Ração Animal/análise , Epinefrina , Glucose
2.
Int J Mol Sci ; 24(7)2023 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-37047139

RESUMO

Multigenerational and transgenerational reproductive toxicity in a model nematode Caenorhabditis elegans has been shown previously after exposure to silver nanoparticles (Ag-NPs) and silver ions (AgNO3). However, there is a limited understanding on the transfer mechanism of the increased reproductive sensitivity to subsequent generations. This study examines changes in DNA methylation at epigenetic mark N6-methyl-2'-deoxyadenosine (6mdA) after multigenerational exposure of C. elegans to pristine and transformed-via-sulfidation Ag-NPs and AgNO3. Levels of 6mdA were measured as 6mdA/dA ratios prior to C. elegans exposure (F0) after two generations of exposure (F2) and two generations of rescue (F4) using high-performance liquid chromatography with tandem mass spectrometry (LC-MS/MS). Although both AgNO3 and Ag-NPs induced multigenerational reproductive toxicity, only AgNO3 exposure caused a significant increase in global 6mdA levels after exposures (F2). However, after two generations of rescue (F4), the 6mdA levels in AgNO3 treatment returned to F0 levels, suggesting other epigenetic modifications may be also involved. No significant changes in global DNA methylation levels were observed after exposure to pristine and sulfidized sAg-NPs. This study demonstrates the involvement of an epigenetic mark in AgNO3 reproductive toxicity and suggests that AgNO3 and Ag-NPs may have different toxicity mechanisms.


Assuntos
Caenorhabditis elegans , Nanopartículas Metálicas , Animais , Caenorhabditis elegans/genética , Nitrato de Prata/toxicidade , Nanopartículas Metálicas/toxicidade , Nanopartículas Metálicas/química , Metilação de DNA , Cromatografia Líquida , Prata/toxicidade , Espectrometria de Massas em Tandem , DNA , Adenina
3.
J Anim Sci ; 1012023 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-36751104

RESUMO

Red clover produces isoflavones, including biochanin A, which have been shown to have microbiological effects on the rumen while also promoting growth in beef cattle. The objective was to determine if supplementation of biochanin A via red clover hay would produce similar effects on the rumen microbiota and improve growth performance of lambs. Twenty-four individually-housed Polypay ram lambs (initial age: 114 ± 1 d; initial weight: 38.1 ± 0.59 kg) were randomly assigned to one of three experimental diets (85:15 concentrate:roughage ratio; N = 8 rams/treatment): CON-control diet in which the roughage component (15.0%, w/w, of the total diet) consisted of orchardgrass hay; 7.5-RC-red clover hay substituted for half (7.5%, w/w, of the total diet) of the roughage component; and 15-RC-the entire roughage component (15.0%, w/w, of the total diet) consisted of red clover hay. Feed intake and weight gain were measured at 14-d intervals for the duration of the 56-d trial, and rumen microbiological measures were assessed on days 0, 28, and 56. Red clover supplementation impacted growth performance of ram lambs. Average daily gains (ADG) were greater in ram lambs supplemented with red clover hay (7.5-RC and 15-RC) than for those fed the CON diet (P < 0.05). Conversely, dry matter intake (DMI) was lower in 7.5-RC and 15-RC than for CON lambs (P = 0.03). Differences in ADG and DMI resulted in greater feed efficiency in ram lambs supplemented with red clover hay (both 7.5-RC and 15-RC) compared to CON (P < 0.01). Rumen microbiota were also altered by red clover supplementation. The total viable number of hyper-ammonia-producing bacteria in 7.5-RC and 15-RC decreased over the course of the experiment and were lower than CON by day 28 (P ≤ 0.04). Amylolytic bacteria were also lower in 15-RC than in CON (P = 0.03), with a trend for lower amylolytic bacteria in 7.5-RC (P = 0.08). In contrast, there was tendency for greater cellulolytic bacteria in red clover supplemented lambs than in CON (P = 0.06). Red clover supplementation also increased fiber utilization, with greater ex vivo dry matter digestibility of hay for both 7.5-RC and 15-RC compared to CON by day 28 (P < 0.03). Results of this study indicate that low levels of red clover hay can elicit production benefits in high-concentrate lamb finishing systems through alteration of the rumen microbiota.


Red clover is rich in the bioactive isoflavone, biochanin A. The goal was to evaluate the impacts of biochanin A supplementation via red clover hay on growth performance of ram lambs as well as the rumen microbiota and fermentation. Low levels of red clover hay inclusion (7.5% and 15.0%, w/w, of the total diet) in high-concentrate finishing diets improved feed efficiency of ram lambs, promoting weight gain while decreasing feed intake. Red clover hay supplementation suppressed ruminal protein-wasting, peptide- and amino-acid degrading and starch-utilizing bacteria compared to control diets without isoflavones. Red clover hay also promoted fiber degrading bacteria and fiber utilization. Lamb growth and microbiological effects of red clover were consistent regardless of supplementation level in the diet. Results of this study indicate that low levels of red clover hay can produce production benefits in lamb finishing systems and demonstrated the efficacy of red clover as a functional feed, or feed with biological activities, in the context of its traditional use as a forage feedstuff.


Assuntos
Rúmen , Trifolium , Bovinos , Ovinos , Animais , Masculino , Rúmen/metabolismo , Ração Animal/análise , Fermentação , Dieta/veterinária , Suplementos Nutricionais , Carneiro Doméstico , Fibras na Dieta/metabolismo , Digestão
4.
Biomolecules ; 13(1)2023 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-36671533

RESUMO

For various reasons, leaves are occasionally lyophilized prior to storage at -80 °C and preparing extracts. Soluble carbohydrate identity and quantity from maize leaf disks were ascertained in two separate years using anion exchange HPLC with pulsed electrochemical detection. Analyses were made from disks after freezing in liquid nitrogen with or without subsequent lyophilization (both years) or directly after removal from plants with or without lyophilization (only in the second year). By adding the lyophilizing step, galactose content consistently increased and, frequently, so did galactoglycerols. The source of the galactose increase with the added lyophilizing step was not due to metabolizing raffinose, as the raffinose synthase (rafs) null mutant leaves, which do not make that trisaccharide, also had a similar increase in galactose content with lyophilization. Apparently, the ester linkages attaching free fatty acids to galactoglycerolipids of the chloroplast are particularly sensitive to cleavage during lyophilization, resulting in increases in galactoglycerols. Regardless of the galactose source, a systematic error is introduced for carbohydrate (and, most likely, also chloroplast mono- or digalactosyldiacylglycerol) amounts when maize leaf samples are lyophilized prior to extraction. The recognition of lyophilization as a source of galactose increase provides a cautionary note for investigators of soluble carbohydrates.


Assuntos
Galactose , Zea mays , Congelamento , Liofilização/métodos , Folhas de Planta
5.
J Clin Med ; 11(4)2022 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-35207254

RESUMO

BACKGROUND: Mitral regurgitation (MR) is common following myocardial infarction (MI). However, the subsequent trajectory of MR, and its impact on long-term outcomes are not well understood. This study aimed to examine the change in MR severity and associated clinical outcomes following MI. METHODS: Records of patients admitted to a single centre between 2016 and 2017 with acute MI treated by percutaneous coronary intervention (PCI) were retrospectively examined. RESULTS: 294/1000 consecutive patients had MR on baseline (pre-discharge) transthoracic echocardiography (TTE), of whom 126 (mean age: 70.9 ± 11.4 years) had at least one follow-up TTE. At baseline, most patients had mild MR (n = 94; 75%), with n = 30 (24%) moderate and n = 2 (2%) severe MR. Significant improvement in MR was observed at the first follow-up TTE (median 9 months from baseline; interquartile range: 3-23), with 36% having reduced severity, compared to 10% having increased MR severity (p < 0.001). Predictors of worsening MR included older age (mean: 75.2 vs. 66.7 years; p = 0.003) and lower creatinine clearance (mean: 60 vs. 81 mL/min, p = 0.015). Change in MR severity was significantly associated with prognosis: 16% with improving MR reached the composite endpoint of death or heart failure hospitalisation at 5 years, versus 44% (p = 0.004) with no change, and 59% (p < 0.001) with worsening MR. CONCLUSIONS: Of patients with follow-up TTE after MI, MR severity improved from baseline in approximately one-third, was stable in around half, with the remainder having worsening MR. Patients with persistent or worsening MR had worse clinical outcomes than those with improving MR.

6.
Front Med (Lausanne) ; 9: 1076583, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36606045

RESUMO

Introduction: Prisons in low-income countries have barriers to providing adequate nutrition to the incarcerated. This perspective discusses a quality improvement program with health education to improve nutrition provided to men in two prisons in Haiti. Methods: Incarcerated men in the National Penitentiary in Port Au Prince and the prison in Mirebalais were the focus of the program. A culturally competent educational intervention was delivered to the prison cooks. Program evaluation included a baseline and a follow-up assessment in 2021 and 2022 in both prisons. Calories, body composition, and nutrition were assessed at both time points. Results: Among 1,060 men assessed in the baseline time period, the mean number of calories per day was 571. Further, 62.5% had a vitamin C intake insufficient to prevent scurvy and 91.6% had vitamin B1 insufficient to prevent beriberi. In the follow-up period, caloric intake decreased to a mean of 454 per day (p < 0.001). The proportion of incarcerated men who had insufficient vitamin C and vitamin B1 to prevent disease increased in the follow-up period. Discussion: The caloric and nutritional intake of incarcerated men in Haitian prisons is poor and is getting worse. The educational intervention with the cooks was not successful due to civil and political strife in the low-income country of Haiti. Standard interventions to improve nutrition need to consider the social context for accessing food.

7.
Data Brief ; 39: 107451, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34703851

RESUMO

Data were collected on patients admitted to the Queen Elizabeth Hospital Birmingham with type-1 myocardial infarction during 2016 and 2017 inclusively, who were treated by percutaneous intervention and had pre-discharge transthoracic echocardiography. The data were obtained from prospectively maintained hospital databases and records. Echocardiography was performed and reported contemporaneously by accredited echocardiographers. The purpose was to understand the prevalence and characteristics of mitral regurgitation (MR) after acute MI, including patients with ST-elevation (STEMI) and non-ST elevation MI (NSTEMI). MR was observed in 294/1000 patients with the following relative severities: mild = 76%, moderate = 21%, severe = 3% [1]. MR was graded by multiparametric quantification including proximal isolvelocity surface area (PISA), vena contracta (VC), effective regurgitant orifice area (EROA) and regurgitant volume (RVol). Amongst all patients with MR (n=294), PISA was performed in 89/294 (30%), VC 75/294 (26%), EROA in 53/294 (18%) and RVol in 26/294 (9%). Amongst patients with moderate or severe MR (n=70), PISA was performed in 57/70 (81%), VC in 55/70 (79%), EROA in 46/70 (66%) and RVol in 25/70 (36%). Characteristics of MR following acute MI were also assessed including frequency of reported leaflet thickness (259/294 = 88%) and mitral annular calcification (102/294 = 35%). Furthermore, the effect of MI on pre-existing MR was investigated and patients with pre-existing MR who continue to have MR after acute MI were found to have progression of MR by one grade in approximately 25% of cases. Finally, using Cox proportional hazards univariate analysis, significant factors associated with mortality in patients with MR post-MI include age (HR 1.065; 95% CI 1.035-1.096; p<0.001), creatinine clearance, (HR 0.981; 95% CI 0.971-0.991; p<0.001), left ventricular ejection fraction (LVEF) (HR 0.966; 95% CI 0.948-0.984; p<0.001), indexed left ventricular end-diastolic volume (LVEDVi) (HR 1.016; 95% CI 1.003-1.029; p=0.018), indexed left ventricular end-systolic volume (LVESVi) (HR 1.021; 95% CI 1.008-1.034; p=0.001), indexed left atrial volume (HR 1.026; 95% CI 1.012-1.039; p<0.001), and those with intermediate likelihood of pulmonary hypertension (pHTN) (HR 2.223; 95% CI 1.126-4.390; p=0.021); or high likelihood of pHTN (HR 5.626; 95% CI 2.189-14.461; p<0.001). Age and LVEF were found to be independent predictors of mortality on multivariate analysis [1].

8.
Am J Cardiol ; 157: 22-32, 2021 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-34417016

RESUMO

Mitral regurgitation (MR) following acute myocardial infarction (AMI) worsens prognosis and reports of prevalence vary significantly. The objective was to determine prevalence, risk factors, and outcomes related to MR following AMI. We identified 1000 consecutive patients admitted with AMI in 2016/17 treated by percutaneous coronary intervention with pre-discharge transthoracic echocardiography. MR was observed in 294 of 1000 (29%), graded as mild (n = 224 [76%]), moderate (n = 61 [21%]) and severe (n = 9 [3%]). Compared with patients without MR, patients with MR were older (70 ± 12 vs 63 ± 13 years; p <0.001), with worse left ventricular ejection fraction (LVEF) (52 ± 15% vs 55 ± 11%; p <0.001) and creatinine clearance (69 ± 33 ml/min vs 90 ± 39 ml/min; p <0.001). They also had higher rates of hypertension (64% vs 55%; p = 0.012), heart failure (3.4% vs 1.1%; p = 0.014), previous MI (28% vs 20%; p = 0.005) and severe flow-limitation in the circumflex (50% vs 33%; p <0.001) or right coronary artery (51% vs 42%; p = 0.014). Prevalence and severity of MR were unaffected by AMI subtype. Revascularization later than 72 hours from symptom-onset was associated with increased likelihood of MR (33% vs 25%; p = 0.036) in patients with non-ST elevation myocardial infarction (NSTEMI). After a mean of 3.2 years, 56 of 288 (19%) patients with untreated MR died. Age and LVEF independently predicted mortality. The presence of even mild MR was associated with increased mortality (p = 0.029), despite accounting for confounders. In conclusion, MR is observed in over one-quarter of patients after AMI and associated with lower survival, even when mild. Prevalence and severity are independent of MI subtype, but MR was more common with delayed revascularization following NSTEMI.


Assuntos
Insuficiência da Valva Mitral/epidemiologia , Infarto do Miocárdio/complicações , Intervenção Coronária Percutânea , Medição de Risco/métodos , Volume Sistólico/fisiologia , Função Ventricular Esquerda/fisiologia , Idoso , Ecocardiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Insuficiência da Valva Mitral/etiologia , Insuficiência da Valva Mitral/fisiopatologia , Infarto do Miocárdio/diagnóstico , Infarto do Miocárdio/cirurgia , Prevalência , Prognóstico , Estudos Prospectivos , Estudos Retrospectivos , Fatores de Risco , Reino Unido/epidemiologia
9.
J Occup Environ Med ; 63(8): 708-712, 2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-33883532

RESUMO

INTRODUCTION: Respiratory problems are prevalent among persons who work in agriculture, however, publications examining the respiratory status in LatinX farmworkers are limited. The purpose of this study is to assess the respiratory status of LatinX farmworkers across New York State. METHODS: This is a retrospective analysis of data gathered from Spanish language OSHA respiratory questionnaires completed between January 2017 and March 2019. The best of three peak flows were compared with predicted normal values derived from regressions using age, gender, and height. RESULTS: Key information was present in 162 Spanish questionnaires. Rates of reported respiratory symptoms were low, less than 2%; 11.7% farmworkers smoked. Best of three peak flows showed a mean of 97.2 ±â€Š16.8% of predicted. DISCUSSION: New York LatinX farmworkers do not appear to have abnormal rates of respiratory symptoms or low peak flows.


Assuntos
Fazendeiros , Migrantes , Agricultura , Hispânico ou Latino , Humanos , Estudos Retrospectivos
10.
Plant Cell Rep ; 40(3): 517-528, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33389047

RESUMO

KEY MESSAGE: Isoflavones are not involved in rhizobial signaling in red clover, but likely play a role in defense in the rhizosphere. Red clover (Trifolium pratense) is a high-quality forage legume, well suited for grazing and hay production in the temperate regions of the world. Like many legumes, red clover produces a number of phenylpropanoid compounds including anthocyanidins, flavan-3-ols, flavanols, flavanones, flavones, and isoflavones. The study of isoflavone biosynthesis and accumulation in legumes has come into the forefront of biomedical and agricultural research due to potential for medicinal, antimicrobial, and environmental implications. CRISPR/Cas9 was used to knock out the function of a key enzyme in the biosynthesis of isoflavones, isoflavone synthase (IFS1). A hemizygous plant carrying a 9-bp deletion in the IFS1 gene was recovered and was intercrossed to obtain homozygous mutant plants. Levels of the isoflavones formononetin, biochanin A and genistein were significantly reduced in the mutant plants. Wild-type and mutant plants were inoculated with rhizobia to test the effect of the mutation on nodulation, but no significant differences were observed, suggesting that these isoflavones do not play important roles in nodulation. Gene expression profiling revealed an increase in expression of the upstream genes producing the precursors for IFS1, namely, phenylalanine ammonium lyase and chalcone synthase, but there were no significant differences in IFS1 gene expression or in the downstream genes in the production of specific isoflavones. Higher expression in genes involved in ethylene response was observed in the mutant plants. This response is normally associated with biotic stress, suggesting that the plants may have been responding to cues in the surrounding rhizosphere due to lower levels of isoflavones.


Assuntos
Isoflavonas/metabolismo , Oxigenases/genética , Proteínas de Plantas/genética , Trifolium/genética , Trifolium/metabolismo , Sistemas CRISPR-Cas , Deleção de Genes , Regulação da Expressão Gênica de Plantas , Genisteína/metabolismo , Isoflavonas/genética , Oxigenases/metabolismo , Proteínas de Plantas/metabolismo , Nodulação/genética , Plantas Geneticamente Modificadas , Rhizobium/fisiologia , Rizosfera
12.
Pest Manag Sci ; 77(4): 1559-1563, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32309902

RESUMO

Herbicide resistance has emerged globally as a serious threat to profitable crop production. FMC promotes integrated weed management approaches including responsible use of existing herbicides, use of non-herbicide weed control tools, awareness about herbicide resistance issues, and support to herbicide resistance management initiatives. FMC is dedicated to developing sustainable weed control solutions through the discovery of new herbicides with novel sites-of-action, effective formulations, advanced application technology, and proactive monitoring for herbicide resistance. © 2020 Society of Chemical Industry.


Assuntos
Resistência a Herbicidas , Herbicidas , Produtos Agrícolas , Herbicidas/farmacologia , Plantas Daninhas , Controle de Plantas Daninhas
13.
J Pharm Sci ; 110(2): 682-686, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33039442

RESUMO

An existing USP(2010) impurity method for levothyroxine drug substance was modified to expand its applicability for the analysis of levothyroxine oral solution (OS) formulation while achieving desirable resolution between the components of OS formulation. When analyzed using modified USP(2010) method, an unknown impurity was detected in one of the levothyroxine OS products. A systematic investigation of unknown impurity was carried out using a combination of chromatographic, mass spectral and physicochemical methods to understand the nature of this unknown impurity. A possible elucidation of chemical structure and reaction mechanism for the formation of this previously unreported impurity was proposed.


Assuntos
Contaminação de Medicamentos , Tiroxina , Cromatografia Líquida de Alta Pressão
14.
Transl Anim Sci ; 4(4): txaa197, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33269340

RESUMO

Gestating ewes consuming ergot alkaloids, from endophyte-infected (E+) tall fescue seed, suffer from intrauterine growth restriction and produce smaller lambs. Arginine (Arg) supplementation has been shown to increase birth weight and oral citrulline (Cit) administration is reported to increase arginine concentrations. Two experiments were conducted to: 1) evaluate if oral supplementation with Cit or water, to ewes consuming E+ fescue seed, increases lamb birth weight and 2) determine the effectiveness of Cit and citrulline:malate as an oral drench and elevating circulating levels of Cit to determine levels and dose frequency. In experiment 1, gestating Suffolk ewes (n = 10) were assigned to one of two treatments [oral drench of citrulline-malate 2:1 (CITM; 81 mg/kg/d of citrulline) or water (TOX)] to start on d 86 of gestation and continued until parturition. Ewes on CITM treatment had decreased (P < 0.05) plasma Arg and Cit concentrations during gestation. At birth, lambs from CITM ewes had reduced (P < 0.05) crude fat and total fat but did not differ (P > 0.05) in birth weight from lambs born to TOX ewes. In experiment 2, nonpregnant Suffolk ewes (n = 3) were assigned to either oral citrulline (CIT; 81 mg/kg/d), citrulline-malate 2:1 (CITM; 81 mg/kg/d of citrulline), or water (CON) drench in a Latin Square design for a treatment period of 4 d with a washout period of 3 d. On d 4, blood samples were collected at 0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, and 18 h post drench. Oral drenching of CIT and CITM increased (P < 0.0001) Cit concentrations within 2 h and levels remained elevated for 6 h. Apparent half-life of elimination for CIT and CITM were 8.484 and 10.392 h, respectively. Our results show that lamb birth weight was not altered with a single oral drench of citrulline-malate; however, lamb body composition was altered. The level and frequency of citrulline dosing may need to be greater in order to observe consistent elevation of Cit/Arg concentrations to determine its effectiveness in mitigating fescue toxicosis.

15.
Chembiochem ; 21(24): 3500-3503, 2020 12 11.
Artigo em Inglês | MEDLINE | ID: mdl-32750193

RESUMO

One promising strategy to combat antibiotic-resistant bacteria is to develop compounds that block bacterial defenses against antibacterial conditions produced by the innate immune system. Salmonella enterica, which causes food-borne gastroenteritis and typhoid fever, requires histidine kinases (HKs) to resist innate immune defenses such as cationic antimicrobial peptides (CAMPs). Herein, we report that 2-aminobenzothiazoles block histidine kinase-dependent phenotypes in Salmonella enterica serotype Typhimurium. We found that 2-aminobenzothiazoles inhibited growth under low Mg2+ , a stressful condition that requires histidine kinase-mediated responses, and decreased expression of the virulence genes pagC and pagK. Furthermore, we discovered that 2-aminobenzothiazoles weaken Salmonella's resistance to polymyxin B and polymyxin E, which are last-line antibiotics and models for host defense CAMPs. These findings raise the possibilities that 2-aminobenzothiazoles can block HK-mediated bacterial defenses and can be used in combination with polymyxins to treat infections caused by Salmonella.


Assuntos
Antibacterianos/farmacologia , Benzotiazóis/farmacologia , Farmacorresistência Bacteriana/efeitos dos fármacos , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Polimixinas/farmacologia , Salmonella enterica/efeitos dos fármacos , Antibacterianos/química , Benzotiazóis/química , Testes de Sensibilidade Microbiana , Estrutura Molecular , Polimixinas/química , Salmonella enterica/genética , Virulência/efeitos dos fármacos
16.
Stud Fam Plann ; 51(2): 193-204, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32538513

RESUMO

To accelerate their demographic transition, sub-Saharan African (SSA) countries must trigger significant and rapid fertility declines. These fertility declines will open a demographic window of opportunity and enable countries to capture a first demographic dividend. Despite some successes, many programs aimed at decreasing fertility in SSA have yielded disappointing results. This commentary argues that better integrated policies will help to accelerate fertility declines in SSA. Such an approach should harness the synergies between a set of four key policy levers: women's empowerment; female education; family planning, reproductive health services, and universal health coverage; and legal reforms. These policy levers should be coupled with renewed commitment from leaders on the continent and increased investments in both family planning and population institutions. By concomitantly investing in these priorities and harnessing the synergies of these policy levers, countries in SSA have a critical opportunity to accelerate their demographic transition, which could help them reach emerging economy status.


Assuntos
Coeficiente de Natalidade , Serviços de Planejamento Familiar/organização & administração , Políticas , África Subsaariana , Países em Desenvolvimento , Empoderamento , Acessibilidade aos Serviços de Saúde/organização & administração , Humanos , Serviços de Saúde Reprodutiva/organização & administração , Fatores Socioeconômicos , Assistência de Saúde Universal
18.
FEBS Lett ; 594(2): 337-357, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31514245

RESUMO

Fumarase C (FumC) catalyzes the reversible conversion of fumarate to S-malate. Previous structural investigations within the superfamily have reported a dynamic structural segment, termed the SS Loop. To date, active-site asymmetry has raised the question of how SS Loop placement affects participation of key residues during the reaction. Herein, we report structural and kinetic analyses from Escherichia coli FumC variants to understand the contribution of SS Loop residues S318, K324, and N326. High-resolution X-ray crystallographic results reveal three distinct FumC active-site conformations; disordered-open, ordered-open, and the newly discovered ordered-closed. Surprisingly, each SS Loop variant has unaffected Michaelis constants coupled to reductions in turnover number. Based upon our structural and functional analyses, we propose structural and catalytic roles for each of the aforementioned residues.


Assuntos
Catálise , Fumarato Hidratase/ultraestrutura , Conformação Proteica , Sequência de Aminoácidos/genética , Domínio Catalítico/genética , Cristalografia por Raios X , Escherichia coli/enzimologia , Fumarato Hidratase/química , Fumarato Hidratase/genética , Cinética , Modelos Moleculares
19.
Health Serv Res Manag Epidemiol ; 6: 2333392819862122, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31384624

RESUMO

INTRODUCTION: The incidence of chronic disease and treatment costs have been steadily increasing in the United States over the past few decades. Primary prevention and healthy lifestyle counseling have been identified as important strategies for reducing health-care costs and chronic disease prevalence. This article seeks to examine decision-makers' experiences and self-perceived roles in guideline and lifestyle counseling implementation in a primary care setting in the United States. METHODS: Qualitative interviews were conducted with administrators at a health-care network in Upstate New York and with state-level administrators, such as insurers. Decision-makers were asked to discuss prevention guidelines and healthy lifestyle counseling, as well as how they support implementation of these initiatives. Interviews were analyzed using a thematic analysis framework and relevant sections of text were sorted using a priori codes. RESULTS: Interviews identified numerous barriers to guideline implementation. These included the complexity and profusion of guidelines, the highly politicized nature of health-care provision, and resistance from providers who sometimes prefer to make decisions autonomously. Barriers to supporting prevention counseling included relatively time-limited patient encounters, the lack of reimbursement mechanisms for counseling, lack of patient resources, and regulatory complexities. CONCLUSIONS: Our research indicates that administrators and administrative structures face barriers to supporting prevention activities such as guideline implementation and healthy lifestyle counseling in primary care settings. They also identified several solutions for addressing existing primary prevention barriers, such as relying on nurses to provide healthy lifestyle support to patients. This article provides an important assessment of institutional readiness to support primary prevention efforts.

20.
J Struct Biol ; 204(3): 513-518, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30339832

RESUMO

DcrB is an 18 kDa lipoprotein that contains a single domain of unknown function. DcrB is found within Enterobacteriaceae, a family of Gram-negative bacteria which includes pathogens that can cause food-borne illness and hospital-acquired infections. In Salmonella enterica serovar Typhimurium, DcrB is up-regulated by conditions that promote the production of known virulence factors. We determined the structure of a truncated form of DcrB from Salmonella to 1.92 Šresolution by X-ray crystallography. This truncated form, DcrBΔ37, contains the entire domain of unknown function but lacks the lipoprotein signal sequence (residues 1-20) as well as residues 21-37. The DcrBΔ37 monomer contains the Mog1p/PsbP-like fold, which is found in functionally diverse proteins in mammals, yeast, plants, and cyanobacteria. Interestingly, DcrBΔ37 crystallized as a domain-swapped homodimer in which the N-terminal ß-hairpin extends from one protomer to interact with the core of the second protomer. This domain-swapping indicates that the N-terminal portion of the Mog1p/PsbP-like fold likely has conformational flexibility. Overall, our results provide the first example of an enterobacterial protein that contains the Mog1p/PsbP-like fold and expands knowledge of the structural and phylogenetic diversity of Mog1p/PsbP-like proteins.


Assuntos
Proteínas de Bactérias/genética , Lipoproteínas/genética , Mutação , Salmonella enterica/genética , Sequência de Aminoácidos , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Dicroísmo Circular , Cristalografia por Raios X , Lipoproteínas/química , Lipoproteínas/metabolismo , Modelos Moleculares , Conformação Proteica , Estrutura Secundária de Proteína , Salmonella enterica/metabolismo
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